This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. SMM laser tweezers used to measure endocytic forces and avidity between Notch coated beads and ligand expressing cells. Correlations between endocytic forces, adhesion strength and Notch transedocytoiss are sought